3DXL issue with DLP-Link Glasses - Page 7 - AVS Forum
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post #181 of 311 Old 12-13-2010, 04:24 AM - Thread Starter
 
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Originally Posted by perfectdark View Post

Can we use IRemitter with thsoe glasses with a DLP front projector and the 3D-XL ? or are weconfined to DLP Link glasses ONLY

Yes,
this is the only solution for 3D-XL to work correctly without loosing the eye sync.
Simply plug an IR transmitter into 3D-XL's VESA port and use the IR glasses. Or you can plug-in wired glasses which only cost from US$10 to 14 each.

Mathew Orman
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post #182 of 311 Old 12-13-2010, 06:53 AM
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JOHNnDENVER,
Could you please post a link your post that describes your configuration for outputting 3D frame seuential 3D video based content to your projector and which uses DLP-Link glasses. As I recall you are using player software which allows you to specify that left eye content is to always be sent first and you have had few or no problems with eye sync reversals?
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post #183 of 311 Old 12-13-2010, 07:15 AM - Thread Starter
 
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Originally Posted by walford View Post

JOHNnDENVER,
Could you please post a link your post that describes your configuration for outputting 3D frame seuential 3D video based content to your projector and which uses DLP-Link glasses. As I recall you are using player software which allows you to specify that left eye content is to always be sent first and you have had few or no problems with eye sync reversals?

It does not matter.
The DLP-Link projector does not know if a frame has left eye content or the right one.
Is it so hard to comprehend?

Mathew Orman
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post #184 of 311 Old 12-13-2010, 07:37 AM
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Quote:
Originally Posted by icester View Post

Yes,
this is the only solution for 3D-XL to work correctly without loosing the eye sync.
Simply plug an IR transmitter into 3D-XL's VESA port and use the IR glasses. Or you can plug-in wired glasses which only cost from US$10 to 14 each.

Mathew Orman

Man ... I'm learning allot but also getting confused ..... I want to buy the glasses before the 3D-XL arrives (i kind told the wife glasses are included, otherwise she would never allow $500 purchase plus glasses )
So Mathew, thanks for all your info ... really appreciated especially since my two emails to Optoma canada have no responseand ther sales #in canada is out of service LOL

If you wouldn't mind can u elaborate on this Vesa port? what it is and how it works? I see it in the specs
Inputs: 2x HDMI 1.4a (HDCP) - audio supported
Outputs: 1x HDMI 1.3 (HDCP) - audio supported, 3-PIN mini DIN (VESA Sync)
Control: 9-pin RS232

Also... my apologies .... so it seems IR glasses are the way to go,, but will they lose sync in a dark home theatre room?
And i am lost as to where i buy these IR Emitter and glasses
I see the below link glasses at my bestbuy but they are $100 each and i still need an emitter
http://www.bestbuy.ca/en-CA/product/...f981a84b08en02
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post #185 of 311 Old 12-13-2010, 07:47 AM - Thread Starter
 
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Quote:
Originally Posted by perfectdark View Post

Man ... I'm learning allot but also getting confused ..... I want to buy the glasses before the 3D-XL arrives (i kind told the wife glasses are included, otherwise she would never allow $500 purchase plus glasses )
So Mathew, thanks for all your info ... really appreciated especially since my two emails to Optoma canada have no responseand ther sales #in canada is out of service LOL

If you wouldn't mind can u elaborate on this Vesa port? what it is and how it works? I see it in the specs
Inputs: 2x HDMI 1.4a (HDCP) - audio supported
Outputs: 1x HDMI 1.3 (HDCP) - audio supported, 3-PIN mini DIN (VESA Sync)
Control: 9-pin RS232

Also... my apologies .... so it seems IR glasses are the way to go,, but will they lose sync in a dark home theatre room?
And i am lost as to where i buy these IR Emitter and glasses
I see the below link glasses at my bestbuy but they are $100 each and i still need an emitter
http://www.bestbuy.ca/en-CA/product/...f981a84b08en02

Here you see tons of it:

http://desc.shop.ebay.com/i.html?_nk...eDesc=1&_rdc=1

Mathew Orman
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post #186 of 311 Old 12-13-2010, 08:04 AM
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Quote:
Originally Posted by icester View Post

Here you see tons of it:

http://desc.shop.ebay.com/i.html?_nk...eDesc=1&_rdc=1

Mathew Orman

are those any good.... generic no names ? like $240 for 4 glasses and an emitter ... seems to good tobe true (even though the glasses look uncomfortable)

any stores (other than ebay) u have links too
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post #187 of 311 Old 12-13-2010, 08:26 AM - Thread Starter
 
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Quote:
Originally Posted by perfectdark View Post

are those any good.... generic no names ? like $240 for 4 glasses and an emitter ... seems to good tobe true (even though the glasses look uncomfortable)

any stores (other than ebay) u have links too

You can get the wireless vesa glasses for around US $25 or US$10 for the wired version.

http://www.alibaba.com/trade/search?...ewAllCategory=

http://www.amazon.com/s/ref=nb_sb_no...lasses&x=0&y=0


http://www.amazon.com/Elsa-wireless-...2257345&sr=8-5

And this link is from 3dtv corp Michael Starks the founder of Stereographics Corp now RealD:

http://www.amazon.com/Glasses-Xbox--...2257462&sr=8-5


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post #188 of 311 Old 12-13-2010, 08:35 AM
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Quote:
Originally Posted by icester View Post

You can get the wireless vesa glasses for around US $25 or US$10 for the wired version.

http://www.alibaba.com/trade/search?...ewAllCategory=

http://www.amazon.com/s/ref=nb_sb_no...lasses&x=0&y=0


http://www.amazon.com/Elsa-wireless-...2257345&sr=8-5

And this link is from 3dtv corp Michael Starks the founder of Stereographics Corp now RealD:

http://www.amazon.com/Glasses-Xbox--...2257462&sr=8-5


Mathew Orman

thanks

but that www.alibaba.com site is minimum 100 pieces

http://www.amazon.com/Elsa-wireless-...2257345&sr=8-5 No one is gonna wear these egly looking things LOL look like a cy borg

will any emitter work with any glasses? if i buy an emitter will them work with any of these glasses http://www.shopcompanion.com/3d+emit...FQTNKgodVmyF5A
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post #189 of 311 Old 12-13-2010, 08:40 AM
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Quote:
Originally Posted by icester View Post

It does not matter.
The DLP-Link projector does not know if a frame has left eye content or the right one.
Is it so hard to comprehend?

Mathew Orman

You're crystal clear, but that is not the end.
It does not mean you'll have to use the frame inverter every time you change the channel.

If the projector initialises the 3D mode in a predictable way (when receiving a new signal, assume the first frame is always left, or it can be always right, it doesn't matter), and the 3DXL also behaves the same way
Then you circumvent the issue of the left/right info not being transmitted from the 3DXL to the projector.
All you may have to do is to set up the frame inverter the first time you use it and then it will always work perfectly.

Passive 3D, forever !
My Full-HD dual-projector passive polarised 3D setup. (really out of date ! I need to update it some day...)

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post #190 of 311 Old 12-13-2010, 08:53 AM - Thread Starter
 
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Quote:
Originally Posted by BlackShark View Post

You're crystal clear, but that is not the end.
It does not mean you'll have to use the frame inverter every time you change the channel.

If the projector initialises the 3D mode in a predictable way (when receiving a new signal, assume the first frame is always left, or it can be always right, it doesn't matter), and the 3DXL also behaves the same way
Then you circumvent the issue of the left/right info not being transmitted from the 3DXL to the projector.
All you may have to do is to set up the frame inverter the first time you use it and then it will always work perfectly.

You are wrong.
Projector does not know if the frame is first, second, last, left, right etc.
And even if you connect 3D-XL the projector does not know anything about the 3D content of a frame becasue 3D-XL outputs the same frame sequential 120 Hz signal that comes in when nVidia is connected to the projector.

The projector has a defective 3D-Link system and even if source would send eye phase sync to it, it would not use it
becasue manufacturer had not implemented the eye sync phase readout circuit or firmware.

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post #191 of 311 Old 12-13-2010, 08:58 AM - Thread Starter
 
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Quote:
Originally Posted by perfectdark View Post

thanks

but that www.alibaba.com site is minimum 100 pieces

http://www.amazon.com/Elsa-wireless-...2257345&sr=8-5 No one is gonna wear these egly looking things LOL look like a cy borg

will any emitter work with any glasses? if i buy an emitter will them work with any of these glasses http://www.shopcompanion.com/3d+emit...FQTNKgodVmyF5A

No,
only emitters for DLP TVs and legacy CRT like the eDimentional IR emitter will work.

Mathew Orman
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post #192 of 311 Old 12-13-2010, 09:04 AM
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Quote:
Originally Posted by BlackShark View Post

It does not mean you'll have to use the frame inverter every time you change the channel.

If the projector initialises the 3D mode in a predictable way (when receiving a new signal, assume the first frame is always left, or it can be always right, it doesn't matter), and the 3DXL also behaves the same way
Then you circumvent the issue of the left/right info not being transmitted from the 3DXL to the projector.
All you may have to do is to set up the frame inverter the first time you use it and then it will always work perfectly.

This makes sense, I believe you are correct Blackshark. I plan on getting the 3D-XL with the included DLP glasses and try it for several days with different sources and see if there are any complexities in dealing with the eye sync problems. If I find I am constantly reversing the sync within the same BD movie or broadcast show then I will consider using the IR glasses with separate emitter.
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The problem is only certain sources can be controlle to always send eitther the left eye or the riight eye content first every time. Once these sources are set up in this matter then the normal or reverse mode synce in DLP-link capable PJ need only be set up once. For ther sources such as the Nvidia 3D player when used for playing games are random as to which frame comes first when the content changes and with them there is a 50% of the eye sync being wrong and Icestart keeps pointing out.
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post #194 of 311 Old 12-13-2010, 09:26 AM - Thread Starter
 
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Originally Posted by HTFAN007 View Post

This makes sense, I believe you are correct Blackshark. I plan on getting the 3D-XL with the included DLP glasses and try it for several days with different sources and see if there are any complexities in dealing with the eye sync problems. If I find I am constantly reversing the sync within the same BD movie or broadcast show then I will consider using the IR glasses with separate emitter.

It all depends on stability of the quad buffer in 3D-XL box.
It it runs uninterrupted even if HDMI 1.4 transmission has a glitch then you may only have to set the eye order
when you power up the projector or 3D-XL box.
But if the quad buffer gets interrupted by HDMI 1.4 glitch then you may have to correct it when the movie is started, pauseed or has a glitch.

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post #195 of 311 Old 12-13-2010, 09:29 AM
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Quote:
Originally Posted by icester View Post

You are wrong.
Projector does not know if the frame is first, second, last, left, right etc.
And even if you connect 3D-XL the projector does not know anything about the 3D content of a frame becasue 3D-XL outputs the same frame sequential 120 Hz signal that comes in when nVidia is connected to the projector.

The projector has a defective 3D-Link system and even if source would send eye phase sync to it, it would not use it
becasue manufacturer had not implemented the eye sync phase readout circuit or firmware.

Mathew Orman

You missed my point again.

The projector sends the DLP-link signal, from the reports quoted by other users, all the glasses have the same polarity (you don't have half the audience with reverse stereo) so this signal contains a left/right information coded somehow somewhere that makes all the glasses in the audience sync identically.

This means that at some point the projector must decide which frame is left and which frame is right, since it doesn't have the information from the source (I totally agree with you here), the projector must then invent it.

The whole point of my argument is "how" does it invent this information.
If this is done in a predictable way then the 3DXL can circumvent the issue. And the most configuration the user will have to do is to set up the inversion switch only the first time he uses the 3DXL and then it will always show the correct image to the correct eye.
(I could be wrong but my guess is that the projector initialises the left/right information with a fixed value determined in the firmware on the first frame received from a new signal, it would be the most logic thing to do)

Quote:
Originally Posted by icester View Post

It all depends on stability of the quad buffer in 3D-XL box.
It it runs uninterrupted even if HDMI 1.4 transmission has a glitch then you may only have to set the eye order
when you power up the projector or 3D-XL box.
But if the quad buffer gets interrupted by HDMI 1.4 glitch then you may have to correct it when the movie is started, pauseed or has a glitch.

Mathew Orman

Well it'd better run uninterrupted, the 3DXL is a piece of hardware dedicated to do just that.
If it were to fail, it would be like having a broken tv that looses sync and would have to resync all the time.
Having the 3DXL fail at keeping the quadbuffer in check would mean the device fails at it's main function.

Passive 3D, forever !
My Full-HD dual-projector passive polarised 3D setup. (really out of date ! I need to update it some day...)

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post #196 of 311 Old 12-13-2010, 09:36 AM - Thread Starter
 
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Originally Posted by walford View Post

The problem is only certain sources can be controlle to always send eitther the left eye or the riight eye content first every time. Once these sources are set up in this matter then the normal or reverse mode synce in DLP-link capable PJ need only be set up once. For ther sources such as the Nvidia 3D player when used for playing games are random as to which frame comes first when the content changes and with them there is a 50% of the eye sync being wrong and Icestart keeps pointing out.

Wrong again.
When you power up the projector does not care what is in any frames that arrive at 120 Hz rate.
So every time you power it up you must make sure that the eye order is correct and for that you need to have the 3D-XL already powered and 3D Blu-ray already playing 3D movie.

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post #197 of 311 Old 12-13-2010, 09:51 AM - Thread Starter
 
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You missed my point again.

The projector sends the DLP-link signal, from the reports quoted by other users, all the glasses have the same polarity (you don't have half the audience with reverse stereo) so this signal contains a sync information coded somehow somewhere that makes all the glasses in the audience sync identically.

This means that at some point the projector must decide which frame is left and which frame is right, since it doesn't have the information from the source (I totally agree with you here), the projector must then invent it.

The whole point of my argument is "how" does it invent this information.
If this is done in a predictable way then the 3DXL can circumvent the issue. And the most configuration the user will have to do is to set up the inversion switch only the first time he uses the 3DXL and then it will always show the correct image to the correct eye.
(I could be wrong but my guess is that the projector initialises the left/right information with a fixed value determined in the firmware on the first frame received from a new signal, it would be the most logic thing to do)


Well it'd better run uninterrupted, the 3DXL is a piece of hardware dedicated to do just that.
If it were to fail, it would be like having a broken tv that looses sync and would have to resync all the time.

Wrong again on both quotes.

1. The projector never knows or cares if a frame contains left or right image or if it is first frame that is receiving since power up.
All it does is to send left or right eye white flash sync codes at the beginning of every new frame. It simply and blindly alternates sending white flashes in a pattern like this LRLRLRLRLRLR and continues uninterrupted until there is a glitch in v-sync input. And if v-sync glitch happens it may flip the eye order relative to content.
An one must punch the eye flip button again.

2.Every time you power 3D-XL there is going to 50% chase that it output correct eye order.

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post #198 of 311 Old 12-13-2010, 10:17 AM
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Quote:
Originally Posted by icester View Post

Wrong again on both quotes.

1. The projector never knows or cares if a frame contains left or right image or if it is first frame that is receiving since power up.
All it does is to send left or right eye white flash sync codes at the beginning of every new frame. It simply and blindly alternates sending white flashes in a pattern like this LRLRLRLRLRLR and continues uninterrupted until there is a glitch in v-sync input. And if v-sync glitch happens it may flip the eye order relative to content.
An one must punch the eye flip button again.

2.Every time you power 3D-XL there is going to 50% chase that it output correct eye order.

Mathew Orman

The point of my question is :

Start with the projector off :
Plug in the projector power plug
Turn the projector on
-> what eye view will the projector tell the glasses to show through DLP-link when the first frame is shown ?
Is it the same everytime you turn your projector on ?

Unplug the HDMI cord from the 3DXL to the projector
The projector goes to standby mode (no source screen)
Plug the hdmi cord again again
-> what eye view will the projector tell the glasses to show through DLP-link on the first frame when the projector starts showing frames again ?
-> is it the same as when you start up the projector ?

Purposely create a perturbation in the hdmi cable to break the sync between the 3DXL and the projector with whatever mean you want to use
The projector detects the data received is garbage and blanks out (error or no source screen)
Stop disturbing the cable
The hdmi input and output chips do whatever they are designed to do to recover the connection (restart/reset/re-handshake/re-sync/whatever)
-> what eye view will the projector tell the glasses to show through DLP-link on the first frame when the projector starts showing frames again ?
-> is it still the same as before ?

Turn off the DLP-link mode in the the projector menu
The glasses should stop blinking
Turn the DLP-link mode back on in the projector menu
-> what eye view will the projector tell the glasses to show through DLP-link on the first frame after you turn it back on ?
-> is the sync reversed or did the projector keep count internally ? Or is it reset to the same as when you start up the projector ?

etc...

Passive 3D, forever !
My Full-HD dual-projector passive polarised 3D setup. (really out of date ! I need to update it some day...)

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post #199 of 311 Old 12-13-2010, 12:02 PM - Thread Starter
 
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Quote:
Originally Posted by BlackShark View Post

The point of my question is :

Start with the projector off :
Plug in the projector power plug
Turn the projector on
-> what eye view will the projector tell the glasses to show through DLP-link when the first frame is shown ?
Is it the same everytime you turn your projector on ?

Unplug the HDMI cord from the 3DXL to the projector
The projector goes to standby mode (no source screen)
Plug the hdmi cord again again
-> what eye view will the projector tell the glasses to show through DLP-link on the first frame when the projector starts showing frames again ?
-> is it the same as when you start up the projector ?

Purposely create a perturbation in the hdmi cable to break the sync between the 3DXL and the projector with whatever mean you want to use
The projector detects the data received is garbage and blanks out (error or no source screen)
Stop disturbing the cable
The hdmi input and output chips do whatever they are designed to do to recover the connection (restart/reset/re-handshake/re-sync/whatever)
-> what eye view will the projector tell the glasses to show through DLP-link on the first frame when the projector starts showing frames again ?
-> is it still the same as before ?

Turn off the DLP-link mode in the the projector menu
The glasses should stop blinking
Turn the DLP-link mode back on in the projector menu
-> what eye view will the projector tell the glasses to show through DLP-link on the first frame after you turn it back on ?
-> is the sync reversed or did the projector keep count internally ? Or is it reset to the same as when you start up the projector ?

etc...

It is irrelevant what is the first eye that gets turned on.
The projector never knows if when turning left eye on the frame contains left eye image.
Inside the DLP-Link projector there is a flip-flop circuit
which flip-flops on every vertical sync pulse.
When it is in flip state is send left eye code to open left eye shutter and when it is in flop state it send the right eye code to open the right eye shutter.
It is incomplete circuit becasue it does not cares of which eye image is in a frame.

In such configuration if projector gets resarted it is a 50% that is would be in sync with 3D content which means that
you going to have to correct it manually.

Mathew Orman
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On the contrary, predictability of the projector is key here.

You're taking a top-to-bottom approach icester.
You want everything to be designed by the specifications in the first place where the source tells which frame is for which eye and then everything will be perfect like when using hdmi1.4.

The problem is we are not in such a configuration for DLP link.
We have to take a different approach here, the hardware is already in the customer's hands and we have to check for predictable behavior in order to find a loop-hole and carfully design the source specifically to adress the problem.

There is a similar issue with 3D vision and modern digital displays. 3D Vision is not a complete system, it's based on a work-around that the CEM rejected (which is why CEM chose hdmi1.4)
In 3D vision's case, there is no direct link between the display's sync and the glasses's sync. Hdmi and DVI do not guarantee that the graphics card ouput vsync and the projector's completed frame will match. It just happened to be the case with CRT monitors because they were analog scanning displays directly driven by the GPU output, but now with digital displays it doesnt't work anymore.

Digital TVs are known to have picture treatment options that create input lag, single chip DLP projectors cannot sync directly with the source by design (pixels are not scanned, they are flashed in sequence by colour) so an input lag of at least one entire frame is mandatory, LCDs are even worse, most LCD displays are known to have a variable input lag that changes over time.
Since the computer does not know when the display is going to start and end it's frame, it has no way of knowing when the glasses should sync : you should get horrible frame inversion on some parts of the screen on LCD monitors, with a single chip DLP projector you should get one of the color sectors assigned to the wrong eye ! How the hell can Nvidia 3D vision work then !!?

Nvidia had to find a loop-hole to make it work :
they only support displays that they have had in their labs, these displays must have a predictable constant input lag that Nvidia keep in a database in the 3Dvision driver.
When using 3D vision, the driver does not sync the GPU output directly, they apply the known display input lag to make the glasses sync match the display, and you get perfect sync again. (except for the unlucky ones who have defective displays where the lag is different and they get huge ghosting at the top or bottom of the frame)


In DLP-link's case sync is guaranteed but you don't know which is left and which is right.
However if the left/right flip-flop circuit is predictable (if it could reset under specific conditions like when the projector does the configuration when changing source or resynchronising with a interrupted source) you could make the 3DXL manage the quadbuffer in such a way that you would not get that random left/right issue.
I know that digital outputs (hdmi and DVI) know when a display is connected or not, they don't just broadcast signals in the hope a receiver just syncs with it.
They identify each other, they share their supported resolutions and framerates in order to set up the connection properly before even sending the first frame. Hdmi can even refuse to send data if HDCP isn't working.
So I know the source has absolute control over the transmission and can be designed to make sure the first frame sent after plugging your cable is always left (or always right).

If both the 3DXL outputs the first frame after initiating the transmission and the projector initialise the DLP-link signal at the first frame received with a constant Left/Right picture, then you'll get a stable working system.
It does not matter any more that the projector does not know which frame is which.
It does not matter any more if the 3DXL sends left and the projector believes it receives right.
Because they behave the same way the offset between the two will be constant. You'll have to set up the eye switch once when you first plug the projector and then it will always be correct.

That is why it is so important for the projector to be predictable, and that is why I emitted this hypothesis.
If it is predictable then this work-around can work and the left/right views will be correct
If it is not predictable then this work-around cannot work and the left/right views will be 50% wrong like it happens with computers.

Passive 3D, forever !
My Full-HD dual-projector passive polarised 3D setup. (really out of date ! I need to update it some day...)

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post #201 of 311 Old 12-13-2010, 02:22 PM - Thread Starter
 
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Sorry,
but you have no idea how 3D content sync works.

DLP-link projectors have no way and no circuitry that would handle 3D content sync.
Nor they can predict it by any assumptions.

Please do not waist my time.

Take it to a Vision Engineering forum and see how many false assumption you've made in your statements.

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post #202 of 311 Old 12-13-2010, 03:01 PM
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I got a time out, so this may not post....

This is the way DLP-Link works. That is why the projo has the invert option.

Not much left to be said, except that even those that report the issue, report it as not being wrong a very high percentage of the time.

It's a big non-issue because it's not an issue, it's as designed.
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post #203 of 311 Old 12-13-2010, 04:46 PM
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Guys,
I'm joining this thread with care -- my intent is to understand the issue and not take sides in a disagreement. For my own sanity and potentially allow others to catch-up, here's a summary of my understanding. Please chime in with any corrections.

1. Optoma DLP-Link projectors with the 3DXL converter insert a white flash between each screen frame. This flash allows DLP-Link glasses to sync with the content.
2. Since it's a white flash only, DLP-link glasses have no data on which eye frame is being displayed (left or right).
3. Because of this, the glasses will sometimes (the frequency of which is under debate) end up out of phase. The result is the 3D effect is reversed.
4. The projector manufacturer's include a phase switch option in their menus and/or remotes to switch phases and correct it if it's reversed.

I don't understand how this would work with multiple users. If more than one person is watching the same screen (a home-theater) it would seem that if any of their glasses were not in view of the screen at the start, then they would have a 50/50 chance of being out-of-sync when they joined. For example, two people are watching a film and a third pulls his glasses out of a drawer and starts watching. If he was out-of-sync, then using the phase switch option in the projector would "fix" his pair of glasses but would "break" the first two.

Another scenario could be one person leaves the room with the glasses. When they return they again could be out of sync.

If my understanding is correct, then it doesn't appear this system could keep all the glasses synced to the proper left/right frame all the time. On the other hand, this scenario is common and must have been have been foreseen by Optoma. I can't see how they could possibly sell it with such a deficiency as the bad press would surface quickly and harshly.

Why didn't they simply place the flash in-between every other frame and then define the flash frame as one of they eyes? For example only flash before the left frame. Perhaps that's what the "blue line code" post was saying???

Looking forward to seeing your feedback.

"Boy you talk a lot about HT, considering you don't have one"
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post #204 of 311 Old 12-13-2010, 04:53 PM
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Can we not end this thread?

Maybe Optoma has forseen these issues and add something to the 3D-XL to correct for this .. who knows until we get the hardware ....
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post #205 of 311 Old 12-13-2010, 05:10 PM
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Quote:
Originally Posted by UneatenFries View Post

I don't understand how this would work with multiple users. If more than one person is watching the same screen (a home-theater) it would seem that if any of their glasses were not in view of the screen at the start, then they would have a 50/50 chance of being out-of-sync when they joined. For example, two people are watching a film and a third pulls his glasses out of a drawer and starts watching. If he was out-of-sync, then using the phase switch option in the projector would "fix" his pair of glasses but would "break" the first two.

Remember, there are 3 components to syncronize:
source
projector
glasses.

in DLP link, the projector doesn't know anything about the source sync. However, the glasses are specifically linked to the projector. Therefore, it's possible for the source and the projector to lose sync, but not possible for projector and glasses. So, it's all or nothing.

Blackshark: I hope you're right, but Optoma doesn't seem to think so (they've now stated through multiple sources that users will need to - I think they phrased it as - "optimize" their 3d experience using the 3d sync invert function.
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post #206 of 311 Old 12-13-2010, 05:31 PM
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Quote:
Originally Posted by defiancecp View Post

in DLP link, the projector doesn't know anything about the source sync. However, the glasses are specifically linked to the projector. Therefore, it's possible for the source and the projector to lose sync, but not possible for projector and glasses. So, it's all or nothing.

Hmmm... perhaps I should clarify my question. I understand how the glasses and projector stay together -- the white flashes before each frame keep them in-sync. What I don't understand is how new glasses introduced to a running video get in the same phase as the other glasses already there. Does that make sense?

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post #207 of 311 Old 12-13-2010, 05:42 PM
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You are right, we are just wasting time here with speculation about outcomes for a system we don't have and for which we don't know enough to conclude.

The projector declares one frame left and the next one right and we don't know if there is any logic or predictability to it, so we won't know in advance how often users will have to switch left and right eye views manually.
We'll get the answer when the product is available

Passive 3D, forever !
My Full-HD dual-projector passive polarised 3D setup. (really out of date ! I need to update it some day...)

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Here it is:

Quote:
Originally Posted by UneatenFries View Post

Guys,
I'm joining this thread with care -- my intent is to understand the issue and not take sides in a disagreement. For my own sanity and potentially allow others to catch-up, here's a summary of my understanding. Please chime in with any corrections.

1. Optoma DLP-Link projectors with the 3DXL converter insert a white flash between each screen frame. This flash allows DLP-Link glasses to sync with the content.

//No, the projector generates flashes by it self and DLP-Link glasses respond by //opening apropriate eye shutter. This just alignes the timming so there is no //posiblility for shutter to open when frame flashing is already in progress.

2. Since it's a white flash only, DLP-link glasses have no data on which eye frame is being displayed (left or right).

//No, the glasses always respond correctly to left and right white flash codes.


3. Because of this, the glasses will sometimes (the frequency of which is under debate) end up out of phase. The result is the 3D effect is reversed.

//No, the glasses are always in sync with projector sent white flash codes.

4. The projector manufacturer's include a phase switch option in their menus and/or remotes to switch phases and correct it if it's reversed.

//No, such switch is on all 3D projectors, 3D TVs and 3D Blu-ray players.
//it is used for forceing correct order in case of wrongly formated source or when //installing new type of third party hardware boxes or LC shutter glasses or passive //glasses.

I don't understand how this would work with multiple users. If more than one person is watching the same screen (a home-theater) it would seem that if any of their glasses were not in view of the screen at the start, then they would have a 50/50 chance of being out-of-sync when they joined. For example, two people are watching a film and a third pulls his glasses out of a drawer and starts watching. If he was out-of-sync, then using the phase switch option in the projector would "fix" his pair of glasses but would "break" the first two.

//No, the DLP-Link glasses always respond to correct white flash codeds so they //instantly are resychronised when in view field again.

Another scenario could be one person leaves the room with the glasses. When they return they again could be out of sync.

//No, see note above

If my understanding is correct, then it doesn't appear this system could keep all the glasses synced to the proper left/right frame all the time. On the other hand, this scenario is common and must have been have been foreseen by Optoma. I can't see how they could possibly sell it with such a deficiency as the bad press would surface quickly and harshly.

//You are reading the bad press and creating more of it as wee speak.
//AVSforum messages show up instantly in google's search results.

Why didn't they simply place the flash in-between every other frame and then define the flash frame as one of they eyes? For example only flash before the left frame. Perhaps that's what the "blue line code" post was saying???

//Why? becasue nVidia monopoly would loose money if third party shutter glasses could
//use blu-line code or VESA port on PC or nVidia card.


Looking forward to seeing your feedback.

//You just got it.
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post #209 of 311 Old 12-13-2010, 08:20 PM - Thread Starter
 
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Quote:
Originally Posted by UneatenFries View Post

Hmmm... perhaps I should clarify my question. I understand how the glasses and projector stay together -- the white flashes before each frame keep them in-sync. What I don't understand is how new glasses introduced to a running video get in the same phase as the other glasses already there. Does that make sense?

It is becasue the projector sends flash codes for left and right eye. If left code is flashed all glasses will open left shutter and if right code is flashed all glasses will open the right shutter. So any new glasses which come to view will instantly and correctly respond to white flash codes.

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post #210 of 311 Old 12-13-2010, 08:38 PM
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Quote:
Originally Posted by icester View Post

It is becasue the projector sends flash codes for left and right eye. If left code is flashed all glasses will open left shutter and if right code is flashed all glasses will open the right shutter. So any new glasses which come to view will instantly and correctly respond to white flash codes.

Mathew Orman

Got it -- that makes sense. So if the L/R from the content info is sent from the projector and to glasses, where is the potential problem where the stereo is reversed? Are you saying that the 3D-XL box is stripping that info from the HDMI data?

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